The Sirui 75mm Leveling Ball Set for R-X Series Tripods features two piece design for use on any tripod with a 75mm bowl and is used to give you the leveling advantages of a ball-based video head while staying within the Sirui R-X tripod system. When the R-X bowl adapter is attached to the tripod in place of a flat mount, the 75mm Leveling Ball secures and levels your flat-base tripod head. Locking screws lock the video head to the RX-75B, to assure the head does not detach while panning the video head.Features: Two piece construction for use on any tripod with a 75mm bowlLocking screws lock the video head to the RX-75B, to assure the head does not detach while panning the video headRugged metal construction for heavy duty usage